When Instagram was released for Windows Phone, Microsoft promoted the app as one that had finally closed the app-gap that many perceived about the mobile platform. The social network, used by millions around the world, has become a sore reminder of how large brands think about the Windows Phone platform.
It was on 3.22.14 that the Instagram beta was last updated and the app has remained unchanged since that day. In essence, this app represents the exact issue Windows Phone fans have expressed tirelessly over the years: It's not the lack of apps, it's the lack of support for the apps that do exist.
Twitter is another good example. While this app is updated more frequently, it lacks features of its iOS and Android counterparts. By all accounts, Twitter's Windows Phone app is a distant second-thought for the company and while it is semi-frequently updated, when it does get new features, it's months or years after the other apps.
Microsoft is aware of this, to no surprise, and they do hope that their universal apps will help to remedy this situation but it will not be an overnight fix. And with no flagship phones coming to Windows Phone users until this summer, don't expect there to be much excitement in the Windows Phone community for several more months.
If you do want to use Instagram on Windows Phone, there are third-party clients available for the OS that do fill the gap but they are far from perfect. For one thing, you are putting your credentials into an app that you have no control over and Instagram could block the app or ban accounts using the app much like Snapchat has recently done.